Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Polar ice may be softer than we thought

22.06.2018

Tübingen and international researchers investigate ice flow speed in northern Greenland, correcting models predicting sea level change

Ice is a material that can flow like a very viscous liquid. In the polar ice sheets, it flows towards the oceans under its own weight. Knowing how fast the ice flows is of crucial importance to predict future sea level rises, particularly under changing climate conditions.

Professors Paul Bons and Ilka Weikusat from the University of Tübingen’s Geosciences Department, working with scientists from the Alfred Wegener Institute in Bremerhaven, the University of Otago (New Zealand) and the Autonomous University of Barcelona (Spain), measured flow velocities at the surface of the northern Greenland Ice Sheet for a new study now published in Geophysical Research Letters. Their analysis of satellite images suggests that the polar ice is softer than scientists believed until now.

The flow has two components: the internal shearing flow that depends on the viscosity of the ice, and basal motion, which is the ice sheet sliding along the bedrock, especially when the ice melts at that base. The satellite images revealed the surface velocities of the ice, which the researchers used to calculate the stresses that drive the flow.

Previous studies indicated that up to 50 percent of the Greenland Ice Sheet is melting at its base. “This new study shows that that is probably overestimated, because previous studies assumed ice to be harder than it actually is,” says Paul Bons. The new assessment significantly reduces the area where basal motion – and therefore basal melting can be expected in the Greenland study area.

“This does not necessarily mean that ice will now enter the oceans more slowly and delay sea-level rise. Instead, the results suggest that the internal deformation of ice is more important than was thought before,” Ilka Weikusat explains. The new findings will be used to adapt the models predicting sea level changes.

The share of ice transport towards the oceans between melting at the base or internal shearing of the whole ice body has to be reconsidered, but cannot be determined from surface data alone. Instead, deep drill cores into fast flowing ice are important, such as the ongoing EastGRIP project in which some of the authors are involved.

Publication:
Bons, P.D., Kleiner, T., Llorens, M.G., Prior, D.J., Sachau, T., Weikusat, I. Jansen, D.
Greenland Ice Sheet – Higher non linearity of ice flow significantly reduces estimated basal motion. Geophysical Research Letters. First published: 19 June 2018. Doi:10.1029/2018GL078356
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL078356

Contact:
Professor Dr. Paul D. Bons
University of Tübingen – Faculty of Science
Geosciences – Structural Geology
Phone +49 7071 29-76469
paul.bons[at]uni-tuebingen.de

Junior Professor Dr. Ilka Weikusat
University of Tübingen – Faculty of Science – Geosciences – Glaciology
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
Phone +49 471 4831 1968
ilka.weikusat[at]uni-tuebingen.de

Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-tuebingen.de/

More articles from Earth Sciences:

nachricht "Airlift" facility: TU Freiberg tests new mining technology in research and training mine
22.10.2019 | Technische Universität Bergakademie Freiberg

nachricht Atmospheric pressure impacts greenhouse gas emissions from leaky oil and gas wells
21.10.2019 | University of British Columbia

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A cavity leads to a strong interaction between light and matter

Researchers have succeeded in creating an efficient quantum-mechanical light-matter interface using a microscopic cavity. Within this cavity, a single photon is emitted and absorbed up to 10 times by an artificial atom. This opens up new prospects for quantum technology, report physicists at the University of Basel and Ruhr-University Bochum in the journal Nature.

Quantum physics describes photons as light particles. Achieving an interaction between a single photon and a single atom is a huge challenge due to the tiny...

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

New deep-water coral discovered

22.10.2019 | Life Sciences

DNA-reeling bacteria yield new insight on how superbugs acquire drug-resistance

22.10.2019 | Life Sciences

Heat Pumps with Climate-Friendly Refrigerant Developed for Indoor Installation

22.10.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>